Boss AW-2 “manual” knob question

[zentropa]

I have had a few of these over the years but sold my last one in around 2012.

I just got another yesterday and for some reason the controls aren’t responding how I remember them so I wanted to ask if anyone else could verify “yeah, that is how it is supposed to be” or “something is wrong with yours.”

When using it in touch sensitive operation (rate/depth all the way CCW), Im finding if i turn the manual knob above 9 o’clock that the effect basically stops happening altogether. Is this common? My memory says my older ones were not this way.

I also find the sensitivity knob has about 1mm of useful sweep in it… just barely on to just a hair more, regardless of if im using single coils or humbuckers. I also dont remember it behaving in this small of a range in my previous ones.

When in modulation mode, the manual knob is barely affecting anything from min to 12 o clock, then it barely does anything from 12 to 4 o clock. 4 and above basically removes the effect again. This is also not how i remember it.

If anyone could verify that it is working properly or if this one is messed up it would be much appreciated. I can return this one if needed.

[Pepe]

I have had an AW-2 years ago. Since it has a lot of hissing noise I sold it on. I remember the control knobs being very BOSS-unusual, meaning: the range of useful knob settings was very limited. But it didn't behave as yours.

Maybe someone has fiddled around with the one trimpot (for the optocoupler) on the board? Did you check if the potentiometer contacts aren't touching anything inside the chassis?

[zentropa]

I was thinking it might be a trimpot issue.

It has a more useful sweep when in oscillate mode, but still kind of goes unusable above 12 o clock (vs ~9 o clock when in touch sensitive mode).

I guess i will open it up before i make a final decision about keeping vs returning.

[zentropa]

Well, I got a chance to open it up and work with the trimpot. Based upon the stiffness of the wires, I am guessing it hadn't been opened up before. The trimpot screw was square-shaped with print on it, which made it easier to know where its starting point was (it was completely centered).

Tried a few adjustments to it and I found that the more CCW I went with it, the better it behaved in touch sensitive mode. When I maxed it CCW it actually sounded quite a bit better and the manual knob had much more usable range to its sweep (it was useful from 7 o'clock to around 4 o'clock) that allowed for it to be dialed in quite precisely. Like... I could find the exact note where the effect would begin to work.

The downside is that when adjusted this way, the modulated wah mode became almost unusable. With the Sensitivity set to minimum (as directed in the instruction manual), there was no effect. I had to turn the sensitivity up somewhat, but too high and it would just go into cocked wah territory and wouldn't begin to modulate until after the note started to decay. Sensitivity too low and it was just sort of crackly op amp distortion and zero modulated effect.

After trying a number of point between max CCW and 50%, I ended up going back to the 50% where it was set to begin with, as anything above that would basically "break" the modulated mode. If I was only going to use it in touch sensitive mode I would probably turn the trimpot CCW again.

When using it in touch sensitive operation (rate/depth all the way CCW), Im finding if i turn the manual knob above 9 o’clock that the effect basically stops happening altogether. Is this common? My memory says my older ones were not this way.

After re-reading this, I realized that I had described it incorrectly before. "effects basically stops happening" = there is no "wah" sound, it just sounds like the sensitivity is set too high and you get the bass rolloff and treble boost without hearing the actual wah part happen.

[Pepe]

Hmmm, that sounds weird. Too bad that there is only one trimpot that affects everything. I suppose that this AW-2 has a technical flaw.

[laurie]

You might have an early version.

If the serial is earlier than ZD44600

• Check R27 - if it is 820R change it to 1k5

• Check R31 - if it is a 20k and 1k5 in series, change it to two 47k resistors in parallel

[zentropa]

Mine is BG51962, august 1994.

If it is just this way, which is different from my previous ones, I am okay with it, I just wanted to make sure nothing was wrong with it.